NBC (GE) says it is negotiating with other potential advertisers for the eight 30- second advertising spots that remain open.

“We’re hearing from a lot of companies that this is a time to show strength and confidence in their brands in a challenging economy,” said Brian Walker, senior director of communications at NBC Sports in New York.

Walker said NBC had a total of around 67 spots for Super Bowl XLIII and has sold about 59, or 88 percent. In September, NBC said 85 percent of the 30-second spots had sold, some for as much as $3 million each. Typically, 60 percent of Super Bowl slots sell by then.

Walker said NBC could technically sell ad spots up to the last minute before the event. He declined to say whether NBC — a unit of NBC Universal, which is owned by General Electric Co. — is facing pressure from companies to discount rates.